See, I think those ribbon threaded scarves are pretty cool... and I want to make one. The problem is, I have no idea what to knit a scarf in so you could thread a ribbon through. The one that I could tell the stitch was crocheted, so it didn't help much.

I think the best way to do it would be to plan how you want the ribbon woven into the scarf, then plan out where you'll need holes for it to go through. Then use *yo, k2tog* (or purl if that's what rown you're on) to leave a little space. You won't increase or decrease, but you'll have a place for your ribbon. Dropped stitches might also work instead of *yo, k2tog*.

"There are two kinds of strengths: the strength to lead, and the strength to follow; the strength to control, and the strength to yield. There are two kinds of power: the power to strip another's soul bare, and the power to stand naked."~Yaldah Tovah

The one from urbanoutfitters is a very simple crocheted granny square done in a fingering or baby weight yarn {probably, as it looks too thin to be a DK or sport}. Basic crocheting skills will get you through that very quickly. The one from torrid looks a lot more like it's woven than knit. Even with the close up, it is hard to tell with the black yarn. My best guess is that it's more of a roving than a spun yarn. To knit a mesh that you could later weave through, I would use larger needles with a dropped st pattern, and knit lengthwise. A few rows of garter in between the drop stitch rows would give you room for your ribbons as well as prviding a solid-looking background for your embellishments.

one question: Does the size needles affect the length of the drop, when you're dropping stitches? Or is it ....something else?

Most definitely! Since the yarn in a dropped stitch is wrapped around the needle several times, a different diameter needle would have a different sized circumference... think Math class back in school!